Transcutaneous Electrical Neural Stimulation (TENS) involves the application of electrical stimulation to a (usually human) subject through leads attached to electrodes in contact with the subject's skin. By electrically stimulating the nerves proximate to the placement of the electrodes, the muscles associated with the nerves may be stimulated, which may produce one or more therapeutic benefits for the subject, including, for example, muscle stimulation, muscle relaxation, or pain relief.
TENS devices may deliver electrical stimulus to a subject at a wide range of frequencies. Common TENS treatments are often classified as either high frequency TENS, with a typical frequency range of 80-100 Hz (80-100 stimuli per second) or low frequency, with a typical frequency range of 0.5-4 Hz, although frequencies outside of these ranges may also be used. High frequency TENS is often used for relieving pain by inhibiting the transmission of pain signals through neural pathways, while low frequency TENS has been found to relax and restore muscle tissue.
Many devices capable of administering TENS are known in the art. Examples of such devices are described in U.S. Pat. Nos. 3,593,422 (the “'422 patent”); 3,797,500 (the “'500 patent”); 3,983,881 (the “'881 patent”); 4,084,595 (the “'595 patent”); 4,174,706 (the “'706 patent”); 4,586,509 (the “'509 patent”); 4,595,010 (the “'010 patent”); and 6,023,642 (the “'642 patent”), the entire disclosures of which are hereby incorporated by reference in their entirety, to the extent that such disclosures are not inconsistent with the present application.